Dish TV - Dish TV scamming people

Dish TV Scam:
On **th Oct ****, I recharged my dish TV with pack of Rs. **** for * month (with ** days free offer). After that next day on **th Oct, around **:** pm I got a call from dish tv agent, and he started with Sir, we've got a free offer for you and blah blah blah....., I instantly told him, No I don't want anything. But again he said sir just listen to this offer as you're our loyal customer we're providing this offer specially for you free of cost. And luckily at that time I was in public transport, so I thought why not just listen to this offer, may be I'm lucky, So I said okay tell me about this. And the agent said Sir we're giving all the channels of Sony free of cost you won't have to pay anything extra, Should I add these channel to your list. So I wanted to confirm this again and asked him I really don't have to pay anything? And He said,No sir It's free of cost. And that was my mistake, at that moment I completely forget about the point that they can reduce the plan of validity and I simply said Yes. then He again asked me to confirm It and I said okay do it.
And the moment call was finished I just got message from dish TV that you've been subscribed to SONY Pack and your new validity will be till **th march ****, while when I recharged it on the **th Oct, my new validity was **th May ****.
Now I understand that there was mistake on my part that I forgot about the validity part. But my complaints are:
(i) Dish TV is supporting this scam as their own agent calls their customers and scam them by hiding some information in the name of offer.
(ii) I never received a call in last *-* year from dish tv as previously I used to recharge for short amount of time like *-* months, but the moment I recharged it for * months pack, they saw an opportunity of scam and called me next day, as they know that most people will forget about the validity period and when they remember about this after *-* months nothing could be done.
(iii) when I called back to their customer support, they simply accepted that maybe our agent forget to mention validity period and we're sorry for this and they simply restored my original plan.
(iv) I never asked them to give me something for free and I paid Rs. **** for their service, then why are they scamming innocent people and why dish tv is supporting these type of scam, somebody should take action against these type of scams.
I want people to know about this scam as most people simply ignore this type of scam as this was only for some *** odd Rs.
Excuse my grammar mistake and let me know if I can add any more details about this. And what I can do against dish tv so that at least they have some fear before scamming other innocent peoples.